Tabs were the default for a long time, so it can be argued that developers who use spaces make a conscious decision and care about clean code more than tab user

Tabs were the default for a long time, so it can be argued that developers who use spaces make a conscious decision and care about clean code more than tab users who just go along with the default. I'm not arguing tabs vs spaces here, but exploring systems and caring about good organization. If you care about clean code, being orderly and organized probably extends to other areas, too, and that helps you make more money. In my experience, developers who mostly use default settings are often unorganized and easily confused. They also know very little about the systems they are working with, because everything outside their IDE doesn't interest them. I'd also bet that many tab users had to check what they use, because they didn't know or care. tl;dr: Developers who change the settings are more dedicated to their job.